Hey you all!

I am taking a neuroscience class and am struggling with the Nernst equation.

I am doing something wrong, because I never seem to get the answer right.

Here is the question, and sorry if I am posting this in the wrong threads:

**Calculate the reversal potential of a calcium selective conductance at 37 Celsius if the intracellular calcium concentration is 1 uM and the extracellular calcium concentration is 2 mM.**
I am assuming I have to convert 1 uM to mM... would be 2000 mm?

I have tried this:

E CA +2 : RT over ZF x IN (Ca+ 2 over 1)

= 8.314 Joules over +2 times 310.15 over 96.500

I keep getting wrong numbers when calculating:

The multiple choice answers are as follows:

1. - 90 mV

2. - 103.5 mV

3. 101.5 mV

4. 203.0 mV

My guess is -103.5, but I don't just want to be guessing. I want to know how to do the equation properly and how to get the correct answer.

PLEASE HELP?!

THANK YOU!!